This invention relates to carbon black production. In one of its aspects this invention relates to carbon black reactors. In another of its aspects this invention relates to the introduction of carbonaceous feedstock into a carbon black reactor. And still another aspect the invention relates to a feedstock nozzle for the introduction of feedstock into a carbon black reactor.
It has been disclosed in U.S. Pat. No. 4,071,496 that the incorporation of a carbon black with a low tint residual, preferably below minus 6, into a rubber composition causes the hysteresis, or heat buildup, of such a rubber composition to be significantly lower than that of a rubber composition incorporating a carbon black with a higher tint residual, while the abrasion resistance of such rubber compositions incorporating these different carbon blacks remains essentially the same. Great importance has, therefore, been placed upon the discovery of methods and apparatuses that are capable of producing a carbon black having low tint residual.
Tint residual is the difference between the measured tint and the tint calculated from the structure, nitrogen surface area and CTAB surface area in accordance with a specific formula. EQU TR=T-[56.0+1.057(CTAB)-0.002745(CTAB).sup.2 -0.2596(DBP)0.201(N.sub.2 SA-CTAB)]
In this formula the abbreviations used have the following meanings and the properties are measured as described:
TR: This is tint residual.
CTAB: This is the surface area of the carbon black measured in accordance with ASTM D3765-79, m.sup.2 /gr.
N.sub.2 SA: This is the surface area of the carbon black measured using nitrogen in accordance with the ASTM method D-3037-71T, m.sup.2 /gm.
Compressed DBP: This is the structure of the carbon black in cc/100 g and is measured in accordance with ASTM D3493-76. This property is also referred to as 24 M4 DBP.
T: This is the tint or tinting strength of the carbon black relative to the industrial reference black IRB No. 3 which has the value of 100. Tint is measured in accordance with ASTM 3265-75. The surface area, as described above as CTAB and N.sub.2 SA is usually an inverse measurement of the nodule size of the carbon black. The structure of the carbon black, expressed above as compressed DBP, is a measure of the complexity of the individual carbon black aggregates or of the number of nodules "fused" together in one carbon black aggregate.
It is therefore an object of this invention to provide a feedstock nozzle suitable for use in the carbon black reactor. It is another object of this invention to provide a carbon black reactor equipped with means for producing low tint residual carbon black. It is still another object of this invention to provide a method for producing low tint residual carbon black.
Other aspects, objects and the various advantages of this invention will become apparent upon a study of this specification, the drawing, and the appended claims.